JPH0724242A - Contaminated air cleaner - Google Patents

Abstract

PURPOSE:To efficiently clean the contaminated air with the soil in which microorganisms are propagated under optimum conditions. CONSTITUTION:Water is supplied to a water-permeable bed 13 from a water supply part 21 to adjust the water content of a soil bed 15, the water in a pan 2101 is heated by a heater 2103 of a heating part 21 to heat the soil bed 15 and to adjust its temp. The soil bed 15 is moistened and heated to some extent to appropriately keep its temp. and humidity, and hence the soil bed 15 in which microorganisms are propagated is kept under optimum conditions. The contaminated air from an underground parking area 5 is passed through the soil bed 15, hence the contaminant in the air is physically adsorbed by the soil bed 15 acting as a filter, the contaminant is efficiently decomposed by the microorganism in the soil bed 15, and the contaminated air is excellently cleaned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polluted air purifying apparatus suitable for purifying air polluted by exhaust gas emitted from an automobile or a boiler of a factory.

[0002]

2. Description of the Related Art For example, in an underground parking lot or a tunnel exclusively for automobiles, exhaust gas emitted from automobiles is filled, so that the air inside is ventilated by a ventilation device or the like. For this reason, the internal polluted air polluted with exhaust gas is released into the atmosphere, which is one of the causes of polluting the external environment such as trees.

Further, in factories having a combustion engine such as a boiler, it is obliged to install an exhaust gas treatment facility for desulfurization and denitration according to the regulations of the law. However, the exhaust gas treatment that is actually carried out in the factory has a desulfurization rate of 90 to 99% and a denitration rate of 7%.
It is about 0 to 90%, and it is hard to say that it is desulfurized and denitrated sufficiently considering that the exhaust gas before treatment is originally high in concentration, and the exhaust gas after treatment is the external environment such as trees. It still contains sufficient concentrations of pollutants to contaminate water.

Further, for removal of nitrogen oxides in exhaust gas, a dry catalytic reduction method, a non-contact catalytic reduction method, or a wet oxidation absorption method is generally used. Since construction costs and running costs are high, considerable cost is required to obtain sufficient processing capacity, and it is technically difficult to install it on the source of moving polluted air such as automobiles. .

Therefore, using soil in which microorganisms are propagated,
It is possible to purify a large amount of contaminated air at low cost by attaching harmful substances in the contaminated air to particles of soil or by decomposing them into harmless substances by microorganisms.

[0006]

When purifying polluted air using soil in which microorganisms are propagated, the environment where the adhesion of harmful substances to soil particles and the absorption of harmful substances by microorganisms is promoted is prepared. However, it is important to improve the purification efficiency, and for that purpose, it is desirable to keep the soil moist to some extent or to keep the soil warm to some extent. The present invention has been made in view of the above points, and an object of the present invention is to provide a polluted air purifying apparatus capable of efficiently purifying polluted air in soil in which microorganisms are propagated under optimum conditions. is there.

[0007]

In order to achieve the above object, the present invention provides a container, a soil layer contained in the container, in which microorganisms can propagate and air can flow, and an air contained in the container. And a water-permeable layer that allows water to flow, an air-flowing unit that allows air to pass from the water-permeable layer to the soil layer, and a water supply unit that supplies water to the water-permeable layer.

Further, the present invention further comprises heating means for heating the soil layer. Further, the present invention provides
The water-permeable layer is disposed below the soil layer, and the heating means is a water pan disposed below the water-permeable layer, and a heater that heats the water in the pan to generate warm water vapor. And an introducing pipe for introducing the warm water vapor into the soil layer.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a polluted air purifying apparatus according to an embodiment of the present invention. The contaminated air purification apparatus of the present embodiment, which is indicated by the overall reference numeral 1 in FIG. 1, purifies contaminated air (not shown) in an underground parking lot 5 in which about 20 vehicles 3 constantly enter and exit, and is an underground parking lot. It is formed by using a landscaping planting site 9 provided in the vicinity of a building 7 having 5.

The polluted air purifying apparatus 1 comprises a container 11, a water permeable layer 13, a soil layer 15, an air pump 17, a water supply section 19, and a heating section 21. The container 11 is formed so as to open upward (in this embodiment, the area is approximately 21 m ² ), and a metal mesh 1101 made of a stainless steel mesh of 5 mm is stretched at a predetermined height inside thereof. Mesh 1101
A chamber 1103 is formed below.

The water permeable layer 13 is made of gravel having a grain size of about 2 cm.
It is laid down to a thickness of 0 cm, housed inside the container 11 and laid on the metal mesh 1101.
The soil layer 15 is made of a soil in which microorganisms can reproduce, for example, black broth, peat moss, and perlite at a volume ratio of 3: 1: 1 to increase the porosity, and a mixture of a small amount of leaf soil and compost as fertilizer. , 50 cm, and is housed inside the container 11 and laid on the water-permeable layer 13.

Kuroboku is the main constituent of the soil layer 15 and is rich in soil microorganisms. Pete moss is used to increase soil organic matter, and perlite is used to increase porosity and improve water permeability and breathability. In addition, a plurality of trees 23 are planted in the soil layer 15 and these containers 1
1, the permeable layer 13, the soil layer 15, and the trees 23 constitute a landscaping planting site 9. The air pump 17 (corresponding to an air flowing means) sends the contaminated air in the underground parking lot 5 into the chamber 1103 of the container 11 via the exhaust pipe 1701.

The water supply unit 19 (corresponding to water supply means) includes a water supply tank 1901, a water supply pipe 1903, a water supply pump 1905,
And an overflow pipe 1907. Water tank 1
901 is directly connected to the water supply and stores water. The water level inside the water supply tank 1901 is kept constant by a ball tap or the like (not shown). The water supply pipe 1903 is arranged from the water supply tank 1901 to the container 11, and a tip 1909 on the container 11 side extends over the entire upper end of the water permeable layer 13 and extends over the upper end of the water permeable layer 13. 1903
At the tip 1909 part of the
Are provided toward the water permeable layer 13.

The water supply pump 1905 is a water supply tank 190.
1 is provided at a water supply pipe 1903 between the container 11 and
It is driven at regular intervals by a timer (not shown) or the like to supply a certain amount of water in the water supply tank 1901 to the water permeable layer 13 via the water supply pipe 1903. Overflow pipe 1907
Is arranged from an intermediate portion in the vertical direction of the chamber 1103 of the container 11 to the water supply tank 1901.
Overflow pipe 190 inserted from above in 901
The tip 1913 of 7 is below the water surface in the water tank 1901.
It is submerged at 00 mm. Thereby, the chamber 110
The static pressure in 3 is maintained at 200 mmAq, and when the static pressure exceeds 3 mmAq, the air in the chamber 1103 is released to the water supply tank 1901 through the overflow pipe 1907.

The heating unit 21 (corresponding to a heating means) has a tray 2101 composed of a container portion below the chamber 1103 to which the overflow pipe 1907 is connected, and a heater 2103 arranged on the tray 2101. The chamber is provided with an inlet pipe 2105 composed of a container portion above the chamber 1103.

The water flowing out of the water permeable layer 13 through the metal mesh 1101 is stored in the receiving tray 2101, and the water overflowing the receiving tray 2101 is released to the water supply tank 1901 through the overflow pipe 1907. Heater 210
3 heats the water in the pan 2101. The heating temperature of the water in the tray 2101 by the heater 2103 is controlled by a thermostat (not shown), and is constantly adjusted to 35 ° C. in this embodiment. The introduction pipe 2105 removes water vapor (not shown) generated by heating by the heater 2103 from the metal mesh 110.
1 and the permeable layer 13 to the soil layer 15.

Next, the operation of the polluted air purifying apparatus 1 of the present embodiment configured as described above and the air purifying action of the soil layer 15 will be described. Exhaust pipe 1 by air pump 17
When the contaminated air in the underground parking lot 5 is sent into the chamber 1103 of the container 11 via 701, the chamber 1103
As long as the static pressure inside does not exceed 200 mmAq, the contaminated air is introduced into the soil layer 15 through the metal mesh 1101 and the water permeable layer 13.

When the contaminated air passes through the soil layer 15,
By the physical action of the soil layer 15 as a filter,
It captures dust in contaminated air and adsorbs impure components such as hydrocarbon gas such as methane. In addition, contaminants such as impure components are decomposed by the microorganisms in the soil layer 15.
Specifically, aerobic microorganisms propagate on the surface of the soil layer 15 or in the portion where air flows inside the soil layer 15,
Anaerobic microorganisms propagate in the portion of the soil layer 15 where air does not flow, and the polluted air is consumed or used for respiration in the fungus body of these microorganisms.
Carbon monoxide is mainly converted into carbon dioxide, and methane gas is mainly decomposed into carbon dioxide and water to remove various pollutants in polluted air.

By the way, in the water permeable layer 13, the water supply pump 1
The water in the water supply tank 1901 is supplied to the water supply pipe 190 by 905.
The water is continuously supplied to the water permeable layer 13 at a constant amount at a constant rate every 3 hours, so that the water permeable layer 13 is always kept at a constant humidity. Therefore, when the contaminated air passes through the soil layer 15 when the contaminated air passes through the soil layer 15, the contaminated air absorbs the water contained in the water permeation layer 13 and contains moisture appropriately. Moisture contained in is not absorbed by contaminated air. Therefore, the soil layer 15 is prevented from being dried, and
The evaporation of water in the soil layer 15 prevents latent heat from being taken away by the contaminated air and prevents the temperature of the soil layer 15 from decreasing.
The humidity and temperature are maintained at an appropriate level, the soil layer 15 in which the microorganisms are propagated is placed under optimum conditions, and the contaminated air is efficiently purified.

Further, the water supplied into the water permeable layer 13 by the water supply pump 1905 is liable to be liable to be due to its own weight.
Through the metal mesh 1101, it is dripped into the chamber 1103 and collected in the pan 2101. The water accumulated in the saucer 2101 is heated by the heater 2103, and warm water vapor is generated by this heating, and the generated warm water vapor is introduced into the soil layer 15 through the introduction pipe 2105, the metal mesh 1101, and the water permeable layer 13. It The soil layer 1501 is heated by this warm water vapor, and the temperature of the soil layer 15 is appropriately maintained in combination with the above-mentioned prevention of temperature decrease due to the prevention of drying, and the soil layer 15 in which the microorganisms are propagated is under the optimum conditions. When left in the air, the polluted air is efficiently purified.

When the polluted air purifying apparatus 1 having the above-described operation and action is operated for 100 days with carbon monoxide and nitrogen dioxide in the polluted air in the underground parking lot 5 being removed,
The average removal rate is about 90% for carbon monoxide and about 8 for nitrogen dioxide.
It was 0%. Further, since the polluted air purifying apparatus 1 of the present embodiment is configured by using the landscaping planting site 9, the static pressure in the chamber 1103 temporarily rises during rainfall, but still 2
It did not exceed 00 mmAq. In addition, after continuous operation 1
On the 00th day, regarding the contaminated air (initial gas) in the chamber 1103 and the air (final gas) after passing through the soil layer 15, the carbon monoxide concentration and the nitrogen dioxide concentration are continuously measured from 8 am to 7 pm. As a result of the respective measurements, as shown in the diagrams of FIGS. 2 and 3, good results were obtained in which carbon monoxide and nitrogen dioxide in the contaminated air in the underground parking lot 5 were substantially removed. .

As described above, in the polluted air purifying apparatus 1 of this embodiment, the water content of the soil layer 15 is adjusted by the water supply section 21 supplying water to the permeable layer 13, and the heater 21 of the heating section 21 is also adjusted.
Since the soil layer 15 is heated and the temperature thereof is adjusted by heating the water in the saucer 2101 by 03, the soil layer 15 can be moistened to some extent and warmed to some extent to maintain its temperature and humidity appropriately. Soil layer 1 where microorganisms have propagated
5 under the optimum conditions, it is possible to efficiently purify the contaminated air.

In this embodiment, the heating part 21 for indirectly heating the soil layer 15 by generating warm water vapor is provided, but the heating part 21 may be omitted, or the heating part 21 may be omitted. Two
Instead of 1, the heater may be provided in the soil layer 15 or on the inner wall of the container 11 in contact with the soil layer 15 to directly heat the soil layer 15. Further, the configurations of the water permeable layer 13 and the soil layer 15 and the ratio of the components may be appropriately changed depending on the conditions of the environment in which the polluted air purification device 1 is installed. Further, the trees 23 planted in the soil layer 15 may be omitted, but the soil layer 1
From the viewpoint of activating the microorganisms in 5, it is preferable to plant them.

In the present embodiment, the polluted air purifying apparatus 1 for removing carbon monoxide and nitrogen dioxide in the polluted air in the underground parking lot 5 has been described.
Removal of various harmful substances in various exhaust gases such as exhaust gas from automobile tunnels and desulfurization and exhaust gas after denitration treatment exhausted from exhaust gas treatment facility installed in a factory with combustion engine such as boiler It goes without saying that it can be applied to.

[Experimental Example] Next, the results of a pollutant air purification experiment conducted using an experimental device constructed along the polluted air purifier 1 will be described. FIG. 4 is an explanatory diagram showing the configurations of the experimental polluted air purification device used in this experiment and its peripheral devices. In the experimental polluted air purifying apparatus shown in FIG. 4, the same constituent elements as those of the polluted air purifying apparatus 1 shown in FIG. 1 are designated by the same reference numerals as those given in FIG. 1, and the description thereof will be omitted.

In the experimental polluted air purifying apparatus 1 of FIG. 4, a container 11 is constructed by welding acrylic discs to the upper and lower ends of an acrylic cylinder having an inner diameter of 36 cm and a height of 100 cm.
As shown in FIG. 5, three container portions 11 are provided at two locations, that is, the upper end portion of the soil layer 15 and the lower portion of the metal mesh 1101.
The container portion 1107 is connected by a flange 1109. Metal mesh 1101
A 3 mm stainless steel net is used for the permeable layer 13, and the permeable layer 13 is formed by laying gravel with a particle size of about 1 cm to a thickness of 10 cm. The soil layer 15 is composed of black broth, peat moss, and perlite of 3: 1: 1. A mixture having a volume ratio is spread over a thickness of 40 cm to form the water-permeable layer 13 and the soil layer 15 in an intermediate container portion 1107 as shown in FIG.
An upper chamber 1111 is defined within the upper container portion 1107. The composition of the soil layer 15 and the ratio of each composition were determined after confirming the water permeability, air permeability and the like in advance by experiments.

Air is introduced into the exhaust pipe 1701 from the air pump 17, carbon monoxide and nitrogen dioxide are introduced from the carbon monoxide cylinder 25 and the nitrogen dioxide cylinder 27, respectively, and the respective flow rates are controlled by the mass flow controller 29. Chamber 1
Introduced into 103. The water level in the water supply tank 1901 of the water supply unit 19 is kept constant by the ball tap 31, the operation cycle of the water supply pump 1905 is controlled by the timer 33, and the heating temperature of the water in the pan 2101 by the heater 2103 is controlled by the thermostat 35. . Further, as shown in FIG. 7, a water supply tank 1901 is arranged below the container 11,
The tip 1913 of the overflow pipe 1907 is submerged to a depth of 200 mm below the water surface in the water supply tank 1901, and the chamber 1
The static pressure inside 103 was kept at 200 mmAq.

As a measurement system, the chamber 1103
A float type flow meter 37 for measuring the flow rate of the artificial polluted air introduced into the air is installed at an exhaust pipe 1701 on the downstream side of the air pump 17, and the water content (pf value) of the soil layer 15 is measured. A total of 39 and a rod-shaped thermometer 41 for measuring the temperature are inserted into the upper part of the soil layer 15, and a static pressure meter 43 for measuring the static pressure in the chamber 1103 is used as the introduction pipe 2
It was connected to the part of the container 11 forming 105.

As an experimental condition, the flow rate of the artificial polluted air sent into the chamber 1103 is 60 liters /
min, the pseudo carbon monoxide concentration in the contaminated air (hereinafter referred to as CO initial gas concentration) is 30.0 pp
Similarly, the concentration of nitrogen dioxide (hereinafter referred to as the concentration of NO ₂ initial gas) was 0.80 ppm, and a purification experiment for carbon monoxide and nitrogen dioxide was conducted for the following three systems.

System (A): Water-permeable layer 1 by water supply unit 19
No water supply to No. 3 and no heating of water in the pan 2101 by the heating unit 21 System (B): Water supply to the permeable layer 13 by the water supply unit 19 (5 minutes per hour, about 200 ml), by the heating unit 21 Water in saucer 2101 is not heated System (C): Water is supplied to water-permeable layer 13 by water supply unit 19 (5 minutes per hour, about 200 ml), water in saucer 2101 is heated by heating unit 21 (water temperature) Three
5 °)

Experiments were carried out for 20 days for each of the above three systems, and the moisture of the soil layer 15 (soil moisture) and the soil layer 1 on the first day, the fifth day, the tenth day, the fifteenth day, and the twentyth day.
5 (soil temperature), carbon monoxide concentration in air in the upper chamber 1111 (hereinafter referred to as CO final gas concentration), nitrogen dioxide concentration (hereinafter referred to as NO ₂ final gas concentration), and chamber When the static pressure inside 1103 was measured, the results shown in FIGS. 8 to 10 were obtained. Note that FIG. 8 shows the experimental results by the system (A), FIG. 9 shows the experimental results by the system (B), and FIG. 10 shows the system (C).
The results of the experiments are shown below.

According to the results of this experiment, in the system (A) in which neither the moisture adjustment of the soil layer 15 by supplying water to the permeable layer 13 nor the heating of the soil layer 15 by heating the water in the saucer 2101 is carried out, after 20 days The carbon monoxide removal rate is 17% and the nitrogen dioxide removal rate is 15%. On the other hand, the permeable layer 1
The water content of the soil layer 15 is adjusted by supplying water to
In the system (B) in which the soil layer 15 is not heated by heating the water in 01, the carbon monoxide removal rate after 20 days is 77% and the nitrogen dioxide removal rate is 66%. In the system (C) that both controls the water content of the soil layer 15 and heats the soil layer 15 by heating the water in the saucer 2101, the carbon monoxide removal rate after 20 days is 89% and the nitrogen dioxide removal rate is 85%. Thus, the present invention has been found to be effective in removing carbon monoxide and nitrogen dioxide.

[0033]

As described above, according to the present invention, a container, a soil layer housed in the container and capable of breeding microorganisms and allowing the flow of air, and a flow of air and water contained in the container. A permeable layer, an air flow means for passing air from the permeable layer to the soil layer, and a water supply means for supplying water to the permeable layer, so that microorganisms were propagated. It is possible to efficiently purify polluted air under optimum conditions in the soil.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a polluted air purifying apparatus according to an embodiment of the present invention.

[FIG. 2] 10 after continuous operation of the polluted air purifier shown in FIG.
It is a diagram which shows the time transition about the carbon monoxide concentration in the initial gas and final gas which were measured on the 0th day.

[Fig. 3] 10 after continuous operation of the polluted air purifier shown in Fig. 1.
It is a diagram which shows the time transition about the nitrogen dioxide concentration in the initial gas and the final gas which were measured on the 0th day.

FIG. 4 is an explanatory diagram showing a configuration of an experimental polluted air purifying apparatus configured along the polluted air purifying apparatus shown in FIG. 1 and peripheral devices thereof.

5 is an explanatory diagram showing a configuration of a container of the polluted air purifier of FIG. 4. FIG.

FIG. 6 is an explanatory diagram showing a configuration of a main part inside a container of the polluted air purifier shown in FIG. 4.

FIG. 7 is an explanatory diagram showing a main configuration of a water supply unit of the polluted air purifier shown in FIG. 4.

FIG. 8 is a diagram showing the results of a purification experiment of the system (A) conducted using the polluted air purifier of FIG. 4 for carbon monoxide and nitrogen dioxide.

9 is a diagram showing the results of a purification experiment of the system (B), which was carried out using the polluted air purification device of FIG. 4 for carbon monoxide and nitrogen dioxide.

10 is a diagram showing the result of a purification experiment of the system (C), which was carried out using the polluted air purifier of FIG. 4 for carbon monoxide and nitrogen dioxide.

[Explanation of symbols]

 1 Contaminated Air Purification Device 11 Container 13 Permeable Layer 15 Soil Layer 17 Air Pump (Air Flow Means) 19 Water Supply Section (Water Supply Means) 21 Heating Section (Heating Means) 2101 Saucepan 2103 Heater 2105 Introducing Pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B01D 53/81 53/62 F24F 3/16 6803-3L B01D 53/34 135 A

Claims (3)

[Claims] 1. A container, a soil layer housed in the container and capable of breeding microorganisms to allow air flow, a water permeable layer housed in the container to allow air and water flow, and the water permeable layer To the soil layer, and an air flow means for supplying air to the water-permeable layer, and a water supply means for supplying water to the permeable layer. 2. The polluted air purifier according to claim 1, further comprising heating means for heating the soil layer. 3. The water-permeable layer is disposed below the soil layer, and the heating means heats the water tray disposed below the water-permeable layer and the water in the tray to generate warm steam. 3. The polluted air purifying apparatus according to claim 2, comprising a heater that generates heat and an introduction pipe that introduces the warm water vapor into the soil layer.